U.S. patent application number 12/934154 was filed with the patent office on 2011-07-21 for method for electrical flashover ignition and combustion of propellent charge, as well as propellent charge and ammunition shot in accordance therewith.
Invention is credited to Johan Dahlberg, Lennart Gustavsson, Ola Stark, Lars-Peter Svanberg.
Application Number | 20110174184 12/934154 |
Document ID | / |
Family ID | 41135796 |
Filed Date | 2011-07-21 |
United States Patent
Application |
20110174184 |
Kind Code |
A1 |
Stark; Ola ; et al. |
July 21, 2011 |
METHOD FOR ELECTRICAL FLASHOVER IGNITION AND COMBUSTION OF
PROPELLENT CHARGE, AS WELL AS PROPELLENT CHARGE AND AMMUNITION SHOT
IN ACCORDANCE THEREWITH
Abstract
The invention relates to a method of in the electrical ignition
of a propellent charge (1) provided with an electrically conductive
surface coating (5) and comprising one or more propellant
components (3), ensuring that ignition and progressive combustion
of the propellent charge take place. The method is characterized in
that said electrically conductive surface coating, when ignition of
the propellent charge is desired, is connected to an electrical
high-voltage source (6), in that said high-voltage source is made
to generate at least one high electrical pulse to said connected
electrically conductive surface coating, and in that said at least
one high electrical pulse produces an instantaneous flashover
ignition of the electrically conductive surface coating of the
propellent charge and of all its propellant components,
simultaneously. The invention also relates to a propellent charge
and to an ammunition shot comprising the propellent charge.
Inventors: |
Stark; Ola; (Hammaro,
SE) ; Gustavsson; Lennart; (Karlskoga, SE) ;
Dahlberg; Johan; (Port Melboume, AU) ; Svanberg;
Lars-Peter; (Solna, SE) |
Family ID: |
41135796 |
Appl. No.: |
12/934154 |
Filed: |
March 23, 2009 |
PCT Filed: |
March 23, 2009 |
PCT NO: |
PCT/SE09/00151 |
371 Date: |
April 6, 2011 |
Current U.S.
Class: |
102/430 ;
102/202.5; 102/283 |
Current CPC
Class: |
F42B 5/08 20130101; F41A
19/58 20130101; F42C 19/0811 20130101 |
Class at
Publication: |
102/430 ;
102/202.5; 102/283 |
International
Class: |
F41A 19/58 20060101
F41A019/58; F42C 19/12 20060101 F42C019/12; F42B 5/16 20060101
F42B005/16; F42B 1/00 20060101 F42B001/00; F42B 5/02 20060101
F42B005/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 1, 2008 |
SE |
0800729-6 |
Claims
1. A method of, in the electrical ignition of a propellent charge
provided with an electrically conductive surface coating and
comprising one or more propellant components, ensuring that
ignition and progressive combustion of the propellent charge takes
place, wherein said electrically conductive surface coating, when
ignition of the propellent charge is desired, is connected to an
electrical high-voltage source, in that said high-voltage source is
made to generate at least one high electrical pulse to said
connected electrically conductive surface coating, and in that said
at least one high electrical pulse produces an instantaneous
flashover ignition of the electrically conductive surface coating
of the propellent charge and of all its propellant components
simultaneously.
2. The method as claimed in claim 1, wherein the propellant
components of the propellent charge, in the form of smaller
geometric units, are arranged and/or packed together into a desired
propellent charge configuration, which propellant components have
preferably been multiperforated with burning channels.
3. The method as claimed in claim 1, wherein at least the majority
of the free outer burning surfaces of the propellent charge, and
inner burning surfaces of the burning channels emanating therefrom,
are provided with said electrically conductive surface coating
prior to the ignition.
4. The method as claimed in of claim 1, wherein at least the
majority of the free outer burning surfaces of the propellant
components incorporated in the propellent charge, and inner burning
surfaces of the burning channels emanating therefrom, are provided
with said electrically conductive surface coating prior to the
make-up into the particular propellent charge and prior to the
ignition.
5. The method as claimed in claim 1, wherein the at least one high
electrical pulse is so rich in energy that said electrically
conductive surface coating is converted into an ionized plasma.
6. The method as claimed in claim 5, wherein the electrical
high-voltage source, which comprises a regulatable pulse unit, is
made to deliver a plurality of additional high electrical pulses
one after the other, and in that the additional high electrical
pulses are supplied to the formed plasma, so that also the
combustion gases which are formed by the chemical combustion of the
propellent charge are ionized, whereby a controllable energy level
and total energy development suppliable with additional electrical
energy are achieved.
7. The method as claimed in claim 1, wherein the energy from said
progressive combustion and the at least one supplied high
electrical pulse or pulses are utilized for the propulsion of at
least one projectile through a barrel.
8. The method as claimed in claim 1, wherein additional electrical
energy, which is regulatable in terms of energy, in addition to the
chemical energy from the combustion of the propellent charge, is
supplied to the propulsion via the additional electrical pulses to
the ionized plasma, whereby it becomes possible to monitor and
control the propulsion of the projectile during the whole or parts
of the acceleration through the barrel.
9. The method as claimed in claim 7, wherein, following a
discharged ammunition shot, the total pressure in the barrel
distributed over time is regulated by means of additional energy
pulses which each create new pressure pulses, the pressure variance
of which over time is made to mutually overlap in such a way that
the total barrel pressure distributed over time is optimized
according to a desired pressure development that always falls short
of the highest permitted maximum pressure of the barrel.
10. The method as claimed in claim 1, wherein the supplied high
electrical pulse or pulses is/are given a voltage strength of about
1,000 Volts to about 50,000 Volts, preferably about 7,000
Volts.
11. The method as claimed in claim 1, wherein the supplied high
electrical pulse or pulses is/are given a current strength of about
3,000-20,000 Amperes.
12. The method as claimed in claim 1, wherein the electrically
conductive surface coating is applied to the whole or parts of the
burning surfaces of the propellent charge with any one of the
methods: galvanization, plating, chemical steam deposition,
sputtering, dipping or painting with electrically conductive
paint.
13. The method as claimed in claim 1, wherein the electrically
conductive surface coating is applied to the whole or parts of the
burning surfaces of the propellent charge as a glue, preferably an
epoxy-based conductive copper coating.
14. The method as claimed in claim 1, wherein when the ambient
temperature is disadvantageous, this disadvantageous temperature is
compensated by adaptation of the supplied electrical energy in
accordance therewith.
15. A propellent charge, provided with an electrically conductive
surface coating intended for electrical ignition, comprising one or
more propellant components, at least one of which is
multiperforated with burning channels, wherein at least the
majority of all the free outer burning surfaces of the propellant
components incorporated in the propellent charge, as well as the
inner burning surfaces of all burning channels originating
therefrom, comprise said electrically conductive surface
coating.
16. The propellent charge as claimed in claim 15, wherein it
comprises a plurality of smaller propellant components in the form
of smaller geometric units which are arranged and/or packed
together in the propellent charge and which are made up into a
certain set volume, preferably matched to the loading space of a
particular ammunition case.
17. The propellent charge as claimed in claim 15, wherein the
electrically conductive surface coating is comprised of an applied
individual material layer, a coating or a composite of a plurality
of different materials, in which at least one is electrically
conductive, which electrically conductive surface coating is
preferably made of or comprising one or more metals or
semiconductors.
18. The propellent charge as claimed in claim 15 wherein the
electrically conductive surface coating comprises one or some of
the metals silver Ag, nickel Ni, zinc Zn, aluminum Al, copper Cu,
iron Fe, cobalt Co, molybdenum Mo, platinum Pt, gold Au or titanium
Ti, and/or one or some of the semiconductors graphite C, germanium
Ge or gallium arsenide GaAs.
19. An ammunition shot, wherein ignition and combustion of the
propellent charge are ensured according to claim 1.
20. An ammunition shot, wherein it comprises a propellent charge
free from percussion primer and ignition generator, as claimed in
claim 1.
21. The ammunition shot as claimed in claim 19, wherein the
ammunition shot further comprises an electrically conductive
ammunition case, which ammunition case is coated with at least one
electrical insulation over substantially the whole of the inner
side of the ammunition case, an input conductor and an output
conductor connected to a high-voltage source, preferably comprising
a pulse unit, and a front projectile part disposed on the
ammunition case.
22. The ammunition shot as claimed in claim 21, wherein the
ammunition shot further comprises a front uninsulated region of the
ammunition case for producing a first electrical contact between
the electrically conductive surface coating on the propellent
charge and the metallic ammunition case, and to which ammunition
case the output conductor is connected, as well as an insulating
case through the back piece of the ammunition case, whereby which
insulating case the input conductor is connected to produce a
second electrical contact to the electrically conductive ignition
coating of the propellent charge for the formation of a closed
electric circuit between the ammunition shot and the high-voltage
source.
23. The ammunition shot as claimed in claim 1, wherein the
ammunition case is constituted by an electrically non-conductive
ammunition case, having a front electrically conductive first
contact through the electrically non-conductive ammunition case
into the electrically conductive ignition coating connected to the
output conductor and a rear electrically conductive second contact
through the electrically non-conductive ammunition case into the
electrically conductive ignition coating connected to the input
conductor, which input and output conductors are connected to the
high-voltage source.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method of, in the
electrical ignition of a propellent charge provided with an
electrically conductive surface coating and comprising one or more
propellant components, ensuring that ignition and progressive
combustion of the propellent charge take place.
[0002] The present invention also relates to a propellent charge,
provided with an electrically conductive surface coating intended
for electrical ignition, comprising one or more propellant
components, at least one of which is multiperforated with burning
channels.
[0003] In addition, the present invention relates to an ammunition
shot intended to be utilized in accordance with the aforementioned
method, as well as to an ammunition shot comprising a propellent
charge according to the invention.
PROBLEM DEFINITION AND PRIOR ART
[0004] The above mention of both propellent charges and propellant
components is explained by the fact that the complete propellent
charges can comprise a number of smaller propellant components in
the form of more or less tightly packed geometric units, grains,
rods, blocks, sheets, tubes, etc, which are arranged and/or packed
together, preferably inside an ammunition case, one against the
other, against the ammunition case and against other components
possibly present in the loading space of the ammunition case and
can also be multiperforated with burning channels, i.e. can
comprise a greater number of mutually spaced perforations, cavities
or holes, etc., which, from the outer side of the particular
geometric unit, can pass wholly or partially through in order, via
the burning channels, to increase the available free surface which
can be ignited of said geometric unit and thus also for the
particular, complete propellent charge. Said free surfaces are
hence also hereinafter referred to as free burning surfaces.
Propellant components and propellent charges of this type are
usually made of some type of gunpowder, so that normally reference
is often made to propellent gunpowder charges, propellent gunpowder
components, granulated gunpowder, gunpowder blocks, propellent
gunpowder sheets, etc. In this patent application, however, is
meant all explosives which may be considered suitable for use
according to the invention, even if just the term gunpowder were to
be stated in the text to follow.
[0005] The mutual spacing between the aforementioned perforations,
the so-called dividing distance, should here be tailored such that
the propellant, and thus the propellent charge, which, when it is
ignited, is intended to begin burning also along the inner burning
surface of said burning channels, acquires a desired progressivity,
i.e. combustion acceleration, and manages to burn itself out within
the designed burning time. Since the propellant burns and is
gasified not only from the outer side of the respective propellant
component, but also inside the burning channels, whereby the
burning channels are gradually widened with strongly increasing
burning surface resulting therefrom, the total burning area will
gradually be increased, which gives the propellant, or propellant
component and the propellent charge, its overall progressivity. The
dividing distance shall thus optimally correspond to double the
desired burning length, in which the burning length is the section
over which the propellant burns during the burning time, since the
propellant will burn from two adjacent burning channels and one
against the other. It is also conceivable that the perforation
leaves a section equivalent to double the desired burning length
unperforated, either in the middle of the propellant component, for
example of the rod or of the particular corresponding geometric
unit (thus after oppositely directed perforation from both
directions), or along the opposite outer side thereof, in the case
of perforation realized only from one side.
[0006] Multiperforated gunpowder in the form of larger blocks,
sheets or, in certain cases, tubes, having perforations arranged at
double the desired burning length apart and distributed evenly over
the whole of its own surface, is not conceptually a new product. By
way of example, reference can be made to U.S. Pat. No. 677,527 and
British patent GB 16,861, both of which describe multiperforated
propellent gunpowder, yet without giving any detailed information
on how close together the particular perforations should lie or on
suitable dimensions of the incorporated perforations. Quite simply,
no such measurement specifications are included in these patent
specifications, since, when the patents came into being in the
1890's, no suitable instruments were available which made it
possible to measure how quickly the gunpowder actually burns. On
the other hand, the author of the patents must be allowed to have
had a certain view of the characteristics which he wished to
extract from a propellent gunpowder charge via multiperforation. It
is thus only in later times that it was realized how close together
the perforations in a multiperforated propellant should actually
lie and how a multiperforated propellant of this type can be
produced, in a technically and economically acceptable manner, with
sufficiently fine perforations. For more details on the production
of multiperforated propellent gunpowder, reference is made to
Swedish patent SE 518 867, from which it can be seen that a
multiperforated modern propellent gunpowder, i.e. for the
propellent charges and ammunition types which are normally used
today, should have perforations having a diameter of about 0.1-1.0
mm and situated at a dividing distance from one another of about
1-6 mm.
[0007] It is previously known to fire propellent charges by means
of an electrical igniter, the function of which can simply be
described as an electrical heating of, expediently, a metal, which
metal, through contact against a primer charge suitable for this
purpose, ignites the primer charge by heating of the contact
surface of the gunpowder against the incandescent metal to its
ignition temperature at, for example, about 180-200.degree. C.,
whereupon the gunpowder in the primer charge spontaneously ignites
and, in turn, ignites a larger propellent charge which is disposed
on and around the electrical igniter inserted inside the particular
cartridge case. The fact that the igniter is disposed inside the
ammunition case means that the total available loading space for
the propellent charge naturally becomes smaller, and thus the
maximum quantity of energy which can be utilized for the propulsion
of a projectile is also reduced.
[0008] There is therefore a desire to find a method and a device in
which a combustion-gas-driven barrel weapon can be fired by means
of an electrical ignition, but in which the total available loading
space of the ammunition case for the propellent charge is not
reduced by an igniter inserted in the propellent charge. Moreover,
the igniter per se entails a cost, since it is consumed for each
fired ammunition shot. The notion of performing an electrical
firing without the aid of an igniter peculiar to the ammunition
shot is not, however, entirely new.
[0009] In U.S. Pat. No. 3,299,812, propellent charges intended for
small-caliber weapons are described, consisting of metal-coated
granulated multihole gunpowder which is initiated, i.e. ignited,
electrically. According to this patent specification, from this
metal-coated granulated gunpowder have also been produced larger
coherent unit charges of more of less densely packed granulated
gunpowder which has been surface-coated in the manner described in
the patent specification, the surface-coated gunpowder grains being
supplied with necessary ignition current via initiation points on
the electrically conductive end face ends of the packaging which is
utilized to hold together said unit charge. The electrical current
supply is thus only for firing the propellent charge at certain,
locally delimited initiation points by a, in relative terms, slow
heating (0.1 to 0.25 seconds), from which initiation points a
gradual, i.e. progressive, spreading of the combustion is then
intended to take place without further external energy influence or
energy supply.
[0010] One of the problems which the invention described in said
document sets out to solve is how a sufficiently homogeneous
ignition of a gunpowder charge for the production of an explosive,
i.e. a gradually accelerating, combustion of the same shall be able
to be realized with only a minimum of supplied electrical energy.
In a trial described in greater detail in the document, the above
described propellent charges consisting of metal-coated granulated
multihole gunpowder are initiated by virtue of a weak electric
current of less than 7 Amperes and only 1.2 Volts from two
parallel-connected standard nickel-cadmium batteries of 4 Amperes
and 1.25 Volts apiece being passed through the surface coating of
the gunpowder grains for about 0.1 to 0.25 seconds and thereby
heating the gunpowder grains adjacent to the surface coating to a
temperature which leads to the spontaneous ignition of the
gunpowder and its gradual spreading through the propellent
charge.
[0011] The quantity of electrical energy which is required for the
ignition is given at as low as 5 Watt seconds per half the quantity
of gunpowder which is present in a .22 caliber rifle cartridge. All
the examples included in this patent specification thus purely
concern an electrical initiation via heating, by means of a minimum
possible weak-current supply, of smaller compact propellent
charges, whose basic component is a granulated metal-coated
multihole gunpowder. In said document U.S. Pat. No. 3,299,812, it
is also stated that silver Ag, nickel Ni, zinc Zn, aluminum Al,
copper Cu, iron Fe, cobalt Co, molybdenum Mo, platinum Pt and gold
Au can be utilized to give granulated gunpowder an electrically
conductive surface coating.
[0012] As previously indicated above, the propellent charges can be
packed together and/or arranged close together in a variety of fits
and volumes, by means of smaller geometric units of multiperforated
propellant, and can thereby be given high load weights, which are
difficult or very often impossible to achieve in any other way in
ammunition. In addition to the previously stated shapes of the
geometric units, it is also possible to cite propellant disks
stacked one on top of the other inside the ammunition case and
having a diameter and thickness which varies according to the inner
side of the case, possibly also provided with holes for parts
inserted into the propellent charge, for example the rear end of
the projectile, etc., thereby enabling the case to be loaded in a
faster, simpler and more effective manner. A more compact and thus
larger propellent charge for each given loading space, i.e. with
higher propellent charge density, gives a larger available energy
quantity, which, for example in a barrel weapon, can be used to
attain a higher initial velocity (V.sub.0), i.e. its muzzle
velocity (V.sub.0) out of the barrel muzzle, for a projectile. A
higher initial velocity (V.sub.0) can be utilized to, for example,
increase the range, improve the penetrability, reduce the period of
flight of the projectile, etc. Great efforts have therefore been
made and continue to be made to obtain a higher and higher muzzle
velocity (V.sub.0) for such projectiles. The possible increase in
velocity in respect of a certain given loading space is, however,
limited. This is due to the fact that the extra quantity of
propellent charge which is introduced into the loading space
through tighter packing, and the additional propellent gases which
are formed therefrom during the combustion, must also themselves be
accelerated through the barrel, see in greater detail below.
[0013] With more compact propellent charges, moreover, the problem
ensues of how an instantaneous, i.e. momentary, and full flashover
ignition of the propellant along all of its burning surfaces
intended for flashover ignition shall be able to be achieved.
Already in charges of conventionally granulated gunpowder, it is a
well known fact that the flashover ignition between the gunpowder
grains often occurs in a slightly random and sporadic manner, so
that an intermittent and, in crossing directions, irregular
spreading of the flashover ignition occurs via one or more
initiation points, which produces an uneven pressure wave through
the propellent charge. This pressure wave, which is created by the
burning gunpowder, can also cross the gunpowder grains, so that
they burn locally more rapidly and then give rise to a resonance
pressure wave, a so-called pendulum pressure, which can increase
the amplitude of the pressure wave to the point where the permitted
maximum pressure of the barrel is exceeded so that the barrel
bursts.
[0014] The basic principle behind the present invention is
therefore that the flashover ignition of all the propellant
incorporated in the propellent charge shall be able to be effected
instantaneously, at the same time, over all the burning surfaces
available for ignition. An instantaneous flashover ignition gives
immediately from the moment of ignition the maximum possible energy
quantity, i.e. with respect to the particular composition,
configuration and arranged burning area, from the propellent charge
used in the firing and thus also the maximum initial generation of
propellent gas for the propulsion of the projectile, at the same
time as the pressure wave is very homogeneous and uniformly
progressive through the propellent charge, since all incorporated
propellant components and the burning surfaces of all the
propellant components are ignited simultaneously. The burning
characteristics of the propellant can therefore be calculated more
precisely in the dimensioning of the propellent charge, since a
full combustion of the propellant can now be assumed and the
previous random ignition between the propellant components has been
eliminated.
[0015] However, the capacity of the propellent charge to generate
propellent gas must be kept at a lower level at the start of the
ballistic sequence in order, as stated above, to prevent the
maximally permitted pressure for the barrel from becoming too
large, while the quantity of generated propellent gas per unit of
time must thereafter strongly increase right up to the end of the
sequence to compensate for the constantly increasing volume inside
the barrel behind the accelerating projectile. At present, this is
normally achieved through the use of ammunition containing a
progressive propellant, for example comprising the aforementioned
multiperforated propellant components, which burn faster toward the
end of the combustion process. The aforementioned
combustion-gas-driven, progressive ammunition too, however, has a
practically possible upper limit for the acceleration of the muzzle
velocity, at about 1800 m/s.
[0016] A number of different propulsion principles are currently
under development for the attainment of said desired higher initial
velocity for various sorts of projectiles, of which propulsion by
means of electrical drive is interesting in respect of the present
invention.
PURPOSE AND CHARACTERIZING FEATURES OF THE INVENTION
[0017] One object of the present invention is thus to provide a new
method, a new propellent charge and a new ammunition shot
comprising the propellent charge, in order to ensure, in the
electrical ignition of the propellent charge, an instantaneous
flashover ignition of said propellent charge, and then especially
in propellent charges comprising various configurations of
multiperforated geometric units of smaller propellant
components.
[0018] A second object of the present invention is to provide a new
method, a new propellent charge and a new ammunition shot
comprising the propellent charge in order to obtain, in the
electrical ignition of the propellent charge, a more accurately
dimensioned and considerably fuller progressive combustion of said
propellent charge and thus a better predetermined energy
development, for example for the propulsion of a substantially
combustion-gas-driven projectile through a barrel.
[0019] Another object of the present invention is to provide a new
method, a new propellent charge and a new ammunition shot
comprising the propellent charge in order to electrically ignite
the propellent charge without the aid of a conventional percussion
primer or ignition generator inserted in the propellent charge,
whereby a larger loading volume and fewer necessary components are
obtained.
[0020] It is also an object to provide a new method, a new
propellent charge and a new ammunition shot comprising the
propellent charge, in order, in addition to the conventional
chemical energy development from a given propellent charge, to
further be able to influence and, at the same time also to control,
a total energy supply for the ignition and propulsion of an earlier
substantially combustion-gas-driven projectile through a barrel,
and then preferably for a substantially greater part of the
combustion process of the propellent charge and, ideally,
throughout the acceleration process of the projectile through each
particular barrel, which method, propellent charge and ammunition
shot should also give a considerably higher initial velocity for
the projectile compared with currently known propellant-gas-driven
barrel weapons, i.e. a desired velocity at the outlet of the barrel
of over 2000 m/s, and this assuming an unchanged projectile weight
and case volume for the particular ammunition.
[0021] A further object of the present invention is to provide a
new method, a new propellent charge and a new ammunition shot
comprising the propellent charge in order to benefit, in the
electrical ignition of the propellent charge, from advantages from
a number of different propulsion principles to achieve a higher
initial velocity for different projectiles, with use being made of
propulsion by means of chemical energy, together with electrical
drive for driving of the projectile. By chemical energy is here
meant the energy stored in chemical bonds between atoms and
molecules, while by electrical drive we mean that additional energy
is supplied electrically to the propulsion.
[0022] Said objects, as well as other aims which are not listed
here, are satisfactorily met within the scope of that which is
stated in the present independent patent claims. Embodiments of the
invention are set out in the dependent patent claims.
[0023] Thus, according to the present invention, a method has been
produced of ensuring that ignition and progressive combustion of
the propellent charge take place in the electrical ignition of a
propellent charge provided with an electrically conductive surface
coating and comprising one or more propellant components, which
method is characterized in that said electrically conductive
surface coating, when ignition of the propellent charge is desired,
is connected to an electrical high-voltage source, in that said
high-voltage source is made to generate at least one high
electrical pulse to said connected electrically conductive surface
coating, and in that said at least one high electrical pulse
produces an instantaneous flashover ignition of the electrically
conductive surface coating of the propellent charge and of all its
propellant components simultaneously.
[0024] According to further aspects of the method according to the
invention: [0025] the propellant components of the propellent
charge, in the form of smaller geometric units, are arranged and/or
packed together into a desired propellent charge configuration,
which propellant components have preferably been multiperforated
with burning channels; [0026] at least the majority of the free
outer burning surfaces of the propellent charge, and inner burning
surfaces of the burning channels emanating therefrom, are provided
with said electrically conductive surface coating prior to the
ignition; [0027] at least the majority of the free outer burning
surfaces of the propellant components incorporated in the
propellent charge, and inner burning surfaces of the burning
channels emanating therefrom, are provided with said electrically
conductive surface coating prior to the make-up into the particular
propellent charge and prior to the ignition; [0028] the at least
one high electrical pulse is so rich in energy that said
electrically conductive surface coating is converted into an
ionized plasma; [0029] the electrical high-voltage source, which
comprises a regulatable pulse unit, is made to deliver a plurality
of additional high electrical pulses one after the other, and in
that the additional high electrical pulses are supplied to the
formed plasma, so that also the combustion gases which are formed
by the chemical combustion of the propellent charge are ionized,
whereby a controllable energy level and total energy development
suppliable with additional electrical energy are achieved; [0030]
the energy from said progressive combustion and the at least one
supplied high electrical pulse or pulses are utilized for the
propulsion of at least one projectile through a barrel; [0031]
additional electrical energy, which is regulatable in terms of
energy, in addition to the chemical energy from the combustion of
the propellent charge, is supplied to the propulsion via the
additional electrical pulses to the ionized plasma, whereby it
becomes possible to monitor and control the propulsion of the
projectile during the whole or parts of the acceleration through
the barrel; [0032] following a discharged ammunition shot, the
total pressure in the barrel distributed over time is regulated by
means of additional energy pulses which each create new pressure
pulses, the pressure variance of which over time is made to
mutually overlap in such a way that the total barrel pressure
distributed over time is optimized according to a desired pressure
development that always falls short of the highest permitted
maximum pressure of the barrel. [0033] the supplied high electrical
pulse or pulses is/are given a voltage strength of about 1,000
Volts to about 50,000 Volts, preferably about 7,000 Volts; [0034]
the supplied high electrical pulse or pulses is/are given a current
strength of about 3,000-20,000 Amperes; [0035] the electrically
conductive surface coating is applied to the whole or parts of the
burning surfaces of the propellent charge with any one of the
methods: galvanization, plating, chemical steam deposition,
sputtering, dipping or painting with electrically conductive paint;
[0036] the electrically conductive surface coating is applied to
the whole or parts of the burning surfaces of the propellent charge
as a glue, preferably an epoxy-based conductive copper coating;
[0037] when the ambient temperature is disadvantageous, this
disadvantageous temperature is compensated by adaptation of the
supplied electrical energy in accordance therewith.
[0038] The propellent charge, according to the present invention,
is characterized in that at least the majority of all the free
outer burning surfaces of the propellant components incorporated in
the propellent charge, as well as the inner burning surfaces of all
burning channels originating therefrom, comprise said electrically
conductive surface coating.
[0039] According to further aspects of the propellent charge
according to the invention: [0040] it comprises a plurality of
smaller propellant components in the form of smaller geometric
units which are arranged and/or packed together in the propellent
charge and which are made up into a certain set volume, preferably
matched to the loading space of a particular ammunition case;
[0041] the electrically conductive surface coating is comprised of
an applied individual material layer, a coating or a composite of a
plurality of different materials, in which at least one is
electrically conductive, which electrically conductive surface
coating is preferably made of or comprising one or more metals or
semiconductors; [0042] the electrically conductive surface coating
comprises one or some of the metals silver Ag, nickel Ni, zinc Zn,
aluminum Al, copper Cu, iron Fe, cobalt Co, molybdenum Mo, platinum
Pt, gold Au or titanium Ti, and/or one or some of the
semiconductors graphite C, germanium Ge or gallium arsenide
GaAs.
[0043] The ammunition shot according to the invention is
characterized in that ignition and combustion of the propellent
charge are ensured according to any one of the specified method
requirements, and in that the ammunition shot comprises a
propellent charge free from percussion primer and ignition
generator, as is defined in the claims.
[0044] According to further aspects of the ammunition according to
the invention: [0045] the ammunition shot further comprises an
electrically conductive ammunition case, which ammunition case is
coated with at least one electrical insulation over substantially
the whole of the inner side of the ammunition case, an input
conductor and an output conductor connected to a high-voltage
source, preferably comprising a pulse unit, and a front projectile
part disposed on the ammunition case; [0046] the ammunition shot
further comprises a front uninsulated region of the ammunition case
for producing a first electrical contact between the electrically
conductive surface coating on the propellent charge and the
metallic ammunition case, and to which ammunition case the output
conductor is connected, as well as an insulating case through the
back piece of the ammunition case, by which insulating case the
input conductor is connected to produce a second electrical contact
to the electrically conductive ignition coating of the propellent
charge for the formation of a closed electric circuit between the
ammunition shot and the high-voltage source; [0047] the ammunition
case is constituted by an electrically non-conductive ammunition
case having a front electrically conductive first contact through
the electrically non-conductive ammunition case into the
electrically conductive ignition coating connected to the output
conductor and a rear electrically conductive second contact through
the electrically non-conductive ammunition case into the
electrically conductive ignition coating connected to the input
conductor, which input and output conductors are connected to the
high-voltage source.
ADVANTAGES AND EFFECTS OF THE INVENTION
[0048] The primary concept behind the present invention is now that
the ignition of the particular multiperforated propellant shall be
carried out electrically via the thin electrically conductive
surface coating, hereinafter referred to, therefore, as the
ignition coating, without any form of separate igniter, such as
percussion primer or ignition generator, inserted inside the
propellant or the ammunition. Since the thin surface coating is in
itself electrically conductive, it only needs to be connected to a
respective input and output line of the electrical high-voltage
source in order for ignition and plasma formation to be realized,
so that, where a metal ammunition case is used, the ammunition case
is expediently disposed against an external electrical contact on
the bottom of the case and another on its neck, whereby an electric
circuit is obtained. Where an electrically insulated case is used,
either coated with or made of electrically insulating material, two
electrical transmission points are instead arranged through the
case insulation to said electrically conductive surface coating. As
a result, the loading space is gained which would otherwise have to
be utilized for the igniter. This loading space which is hence
released can thus be utilized to increase the load weight for the
ammunition and thus the effect of the charge and of the ammunition.
At the same time, the very use of geometric units of
multiperforated propellant components in the charge already implies
possibilities of making up compact propellent charges with very
high load weights and thus with very high energy content, at the
same time as the electrical ignition principle according to the
present invention implies a possibility for the momentary flashover
ignition of all propellant components incorporated in the
particular propellent charge, both along their outer sides and
inside the burning channels of all these components, by virtue of
the fact that the burning surfaces thereof are provided with
electrically conductive ignition coatings. Taken together, all this
provides a very good progressivity with wholly predetermined energy
development and exact burning time for propellent charges of this
type, at the same time as the risk of emergence of the pendulum
pressures which are so dreaded in an artillery context has been
able to be wholly eliminated.
[0049] Another advantage of the electrical ignition principle
according to the invention is that this is very well suited to the
initiation of propellent charges in so-called telescopic
ammunition, i.e. such ammunition in which the projectile itself is
disposed far into the space which is otherwise primarily taken up
by the propellent charge and in which, therefore, parts of the
propellent charge surround the rear part of the projectile. An
often occurring problem with such ammunition has namely previously
been that the flashover ignition of the propellent charge easily
became uneven, in that the rear part of the projectile screened off
parts of the propellent charge in the flashover ignition and during
the continued combustion process, resulting in the emergence of the
aforementioned pendulum pressure.
[0050] The electrical ignition principle according to the invention
in a more refined form states that each propellant component in its
entirety is coated with a surface-covering ignition coating, or
that at least the majority of all the free outer burning surfaces
of propellant components incorporated in the propellent charge, as
well as the inner burning surfaces of all burning channels
originating therefrom, are provided prior to the ignition with an
electrically conductive surface coating, which, upon the desired
initiation of the propellant, is connected to a high-voltage
source, whereupon said ignition coating is converted into an
electrically conductive plasma, see further clarification below,
which instantaneously ignites the propellant over all the burning
surfaces provided with said surface coating, i.e. that a
surface-coating plasma is produced. In multiperforated propellants,
it is thus an advantage if the electrically conductive surface
coating (the ignition coating) also extends down into all
perforations and other holes, etc. which have been arranged with
the aim of constituting burning channels or burning surfaces, since
an instantaneous flashover ignition of the propellant is then
obtained even inside and along these spaces and surfaces. It can
also be imagined that a propellent charge is first made up out of
preferably multiperforated, variously shaped propellant components
into a certain propellent charge configuration, for example
according to the internal dimension of a particular ammunition
case, and is then provided with the electrically conductive
ignition coating over its free surfaces and down into the inner
surfaces of the burning channels, so that the non-free surfaces
placed one against the other thus remain deprived.
[0051] Note that the ignition according to the invention is thus
not realized via a slow gradual weak-current heating of a locally
situated initiation point until a chemical spontaneous ignition
temperature is attained, but rather via a momentary "physical
plasmafication", i.e. a vaporization and ionization of the
evaporation gases which have been formed by the electrically
conductive surface coating universally at once with the aid of very
high electrical energy supplied from the high-voltage source.
[0052] Through utilization of the extremely hot, electrically
conductive and, in terms of energy, controllable plasma generated
via the high-voltage source and the ignition coating, according to
the present invention the sought-after instantaneous and full
flashover ignition of all the burning surfaces prepared for
flashover ignition is now achieved in even the most compact of all
propellent charges with the greatest load weights and the highest
propellent charge density which can currently in any way be made up
of various configurations of layers, arranged closely together, of
shaped geometric units of multiperforated propellant components and
types of explosive.
[0053] A further and appreciable advantage with the present
invention is thus that it becomes possible to monitor and control
the propulsion of the projectile during the whole or parts of the
acceleration through the barrel, since additional, in terms of
energy, regulatable electrical energy, in addition to the chemical
energy from the combustion of the propellent charge, can be
supplied to the propulsion via the ionized plasma.
[0054] Also the fact that in the present invention the electrically
conductive surface coating replaces the impact-sensitive and
tear-sensitive primer cap of the conventional mechanical percussion
primer offers the advantage that the ammunition can no longer be
accidentally triggered by a minor shock or shaking, for example by
being dropped during handling or transport.
LIST OF FIGURES
[0055] The invention will be described in greater detail below with
reference to the appended figures, in which:
[0056] FIG. 1, according to the invention, schematically shows a
multiperforated propellant component in the form of a propellant
block comprising an applied electrically conductive surface coating
and which propellant component has been connected to a high-voltage
source comprising a pulse unit,
[0057] FIG. 2 schematically shows a corner portion of the
propellant component according to FIG. 1 in cross-sectional
perspective, i.e. a top surface and a side surface, and a
cross-sectional area having three rows of burning channels with
inner burning surfaces, which surfaces and channels comprise
surface coatings of electrically conductive material which are
arranged thereon or therein,
[0058] FIG. 3 schematically shows a cross section of an ammunition
shot configured in accordance with one embodiment of the present
invention, which ammunition shot is connected to a schematically
shown high-voltage source via an input conductor and an output
conductor.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0059] FIG. 1 shows an embodiment of a multiperforated propellant
component 3 incorporated in a propellent charge 1 and
multiperforated by means of burning channels 2, here especially in
the form of a rectangular propellant block, which, according to the
invention, via a covering, electrically conductive surface coating
5 applied over certain or all free burning surfaces 4 existing for
ignition, see FIG. 2, (also hereinafter referred to as the ignition
coating), has been prepared for an instantaneous electrical
flashover ignition, and which propellant component 3, together with
other propellant components existing in the particular propellent
charge 1, has been connected to a high-voltage source 6 (shown
schematically) comprising a pulse unit 7 for the production of a
pulsed plasma, which plasma realizes the desired instantaneous
flashover ignition (hereinafter referred to as plasma ignition), a
controllable progressive combustion of the particular propellent
charge 1, as well as a, in terms of energy, regulatable energy
supply to the combustion process, preferably for the realization of
a much more effective propulsion and at a significantly higher
muzzle velocity (V.sub.o) of a projectile along a barrel (not shown
in detail).
[0060] In FIG. 2, a corner portion of the propellant component 3
according to FIG. 1 is shown schematically in cross-sectional
perspective, i.e. here a multihole gunpowder having two outer free
burning surfaces 4, consisting of a top surface and a side surface,
and a cross-sectional surface having three rows of burning channels
2 with inner burning surfaces 4, which outer and inner burning
surfaces 4 comprise surface coatings 5 of electrically conductive
material which are arranged thereon.
[0061] FIG. 3 shows in schematic representation a cross-section of
an ammunition shot 8 configured in accordance with one embodiment
of the present invention, containing a propellent charge 1 which is
free from percussion primer and from ignition generator and is
multiperforated with burning channels 2. The ammunition shot 8,
according to the shown embodiment, comprises an electrically
conductive, expediently metallic, ammunition case 9, which
ammunition case 9 is lined with at least one internal electrical
insulation 10, which electrical insulation 10 extends over
substantially the whole of the inner side of the ammunition case 9
(and outer side in the case also of an external electrical
insulation), except in a smaller uninsulated region 11 close to the
neck opening 12 of the ammunition case 9, for the realization of an
electrical contact between the electrically conductive surface
coating 5 on the propellent charge 1 and the metallic ammunition
case 9. The ammunition shot 8 and the propellent charge 1 are
further connected, via an input conductor 13 and an output
conductor 14, to the high-voltage source 6 (shown schematically),
preferably also comprising the aforementioned pulse unit 7. In
order to avoid a short-circuit, the shown ammunition case 9 is
arranged with an insulating case 15 through the back piece 16 of
the ammunition case 9, by which insulating case 15 the input
conductor 13 is connected to the electrically conductive ignition
coating 5 of the propellent charge 1. The ammunition shot 8 also
has a front projectile 17, which is fitted in the neck opening 12
of the ammunition case 9 and which projectile 17 bears against the
front end 18 of the propellent charge 1.
[0062] In another embodiment (not shown), the ammunition case can
be constituted by an electrically non-conductive ammunition case,
for example made of plastic or fiberglass, whereupon the
aforementioned insulating case 15 (shown in FIG. 3) through the
back piece 16 of the ammunition case 9 becomes superfluous, while
the small uninsulated region 11 close to the above-situated neck
opening 12 of the ammunition case 9 is replaced by an electrically
conductive contact point or contact region (not shown) through the
electrically non-conductive ammunition case into the electrically
conductive ignition coating. It is then also necessary for an
electrical connection to be arranged along the longitudinal side of
the case in order to produce a closed electric circuit to allow the
ammunition shot to be fired. It is also conceivable for the barrel
of the particular weapon to be utilized or especially equipped to
form a closed electric circuit for the electric current, in which
case special regard should be given to ensuring the electrical
safety for staff and equipment as a consequence of the barrel
having been made live.
[0063] By plasma ignition and pulsed plasma is meant in the present
invention that said surface coating 5 of electrically conductive
material, coating or composite of a plurality of different
materials, preferably made of or comprising one or more metals or
semiconductors, via one or more very high electrical pulses, is
instantaneously vaporized and ionized into the so-called plasma,
i.e. into an aggregation state in which the electrons have been
separated from the atomic nuclei and have in themselves become
electrically conductive, which plasma, during the whole or parts of
the combustion and/or acceleration process, via new electrical
pulses, can either be substantially maintained at a set energy
level or gradually changed to a desired energy level which
preferably implies an increase to an energy level which is
significantly higher than the natural chemical energy level of the
propellant. The extremely high temperature (about 10,000.degree.
C.) of the plasma, to compare with the ignition temperature of a
herein exemplified gunpowder of about 180-200.degree. C. and
combustion temperature of around 1,000.degree. C., influences the
combustion of the propellent charge 1 in a number of positive
aspects, which aspects together can be utilized, for example, to
obtain said desired higher muzzle velocity for the projectile or
projectiles of the particular ammunition.
[0064] For example, it is possible via the plasma to make the
propellent charge 1 burn faster toward the end of the combustion
process, i.e. substantially improve the progressivity of the
propellent charge. Hence a greater quantity of propellent charge 1
is burnt before the projectile leaves the barrel, so that the
quantity of propellent charge 1 can be increased for each given
ammunition case. Moreover, more energy is obtained from the same
quantity of propellent charge, by virtue of a fuller combustion.
More modern propellent charges and newly developed, better
propellant types, which are not normally used in connection with
propellent charges or which cannot be ignited with conventional
percussion primers, such as propellant with high energy content and
low molecular weight for the propellent gases including
multiperforated propellant and certain chemically surface-treated
propellant types, can now be utilized through the use of the plasma
ignition according to the present invention. If the ambient
temperature or the temperature of the propellent gases is
disadvantageous, it is also possible to compensate for this in a
much simpler way, since the quantity of supplied electrical energy
can be varied, i.e. increased or reduced. The total pressure curve,
i.e. the total pressure in the barrel caused by the combustion of
the propellent charge and the additionally supplied electrical
energy distributed over time, which is obtained for the particular
barrel when a shot has been discharged, can thus be tailored such
that said pressure curve does not exceed the permitted maximum
pressure of the barrel and such that the pressure in the barrel
distributed over time (the pressure variance) is either optimized
according to a desired pressure development or is always as optimal
as possible, i.e. the individual pressure curves for each pressure
pulse caused by a respective electrical energy pulse mutually
overlap in such a way that the pressure troughs of the total
pressure curve are minimized.
[0065] Problems with uneven ignition of the propellent charge 1,
and the propellant components 3 existing in the propellent charge
1, are eliminated, since the plasma ignition of the propellent
charge 1 takes place simultaneously over all burning surfaces 4
accessible by the plasma. This is especially advantageous in the
ignition of granulated propellant or in perforated 2 propellent
charges 1, in which a conventional ignition, which always occurs at
and from an initiation point determined by the igniter, and not
simultaneously over the whole of the voltage-exposed surface
coating 5, as is the case in the present invention, only produces a
running ignition which is spread from contact surface to contact
surface, so that varying grain sizes, degrees of packaging, number
and direction of perforations, etc. acquire a much greater
influence on the combustion process than in the case of the plasma,
which spreads more easily and more rapidly and which, via
current/voltage pulses, influences the process everywhere at once.
The current/voltage pulse(s) delivered from the pulse unit 7 of the
high-voltage source 6 namely follow the path through the formed
plasma, which plasma has a very high conductivity due to the
ionization of the molecules which are formed in the gasification of
the ignition coating 5 and which ionization is replenished with
ions from a further ionization of the combustion gases of the
propellant, so that each new pulse directly, i.e. instantaneously
influences, on the one hand, each existing burning surface 4 of the
propellent charge 1 and, on the other hand, the formed propellent
gases which are reached by the plasma. The ability of the
electrically conductive ignition coating 5 to be applied also
inside the burning channels 2 means that the instantaneous plasma
formation, and the contingent other advantages described in this
text, are achieved here too.
[0066] For example, by sending a plurality of current/voltage
pulses with a certain set strength and energy content, duration,
variance and interval one after the other through the plasma, it is
possible to control the plasma, and thus the pressure in the barrel
from the formed propellent gases can be substantially monitored
and/or maintained for a substantially longer period at a level
desired for the particular barrel. Thus, a progressive acceleration
of the projectile 17 for a longer part of the firing process is
obtained, at the same time as the maximum compressive strength of
the barrel is never exceeded.
[0067] Functional Description
[0068] Upon firing of an ammunition shot 8 situated in the chamber
position of a weapon system prepared for electrical firing, a
high-voltage source 6 is connected to the electrically conductive
ignition coating 5 of the propellent charge 1. The high-voltage
source 6, for example a pulse unit 7 (Pulse Power Supply, PPS), is
made to deliver at least one strong pulse, though preferably a
plurality of pulses, comprising a high current strength and/or a
high voltage. Where a pulse unit is used, this comprises capacitors
for delivering voltage of about 1,000-50,000 Volts. The current
strength used amounted to about 7,000 Amperes. The pulse time can
be as low as 0.001 seconds, i.e. up to 250 times faster than in the
aforementioned example involving heating for spontaneous ignition,
in which, moreover, a minimum of supplied energy (7 Amperes at 1.2
Volts) was sought. Other known PPS units comprising thyristor
converters can generate pulses of about 4,000 Volts combined with a
current strength of up to 20,000 Amperes.
[0069] The strong pulse or pulses, for example about 1-4 pulses,
instantaneously heat the electrical ignition coating 5 over 100% of
its surface to such a high temperature that it is gasified and
ionized into the very hot plasma. The heat from this plasma then,
in turn, gasifies the propellent charge 1 into the propellent gases
which push out the projectile 17 through the barrel of the weapon,
and which propellent gases, too, are ionized by the following
pulses. The performance of such Electro-Thermal-Chemical (ETC)
weapons is influenced not only by the total supplied energy, but
also by the length of the pulses and where the plasma is allowed to
act.
[0070] The interval between the pulses can, of course, be varied
according to prevailing conditions at the moment of firing and
according to specific characteristics of the present weapon system,
so that an improved flashover ignition of and effect from the
propellent charge 1 is obtained. This is realized by the
advantageous characteristics of the particular plasma being
substantially maintained between the pulses, since the plasma does
not have time to die down or fade to a level which is unfavourable
for the ignition and combustion of the propellent charge 1.
Moreover, the separate pulses can be made to act upon the
electrical ignition coating 5 and the propellent charge 1 step by
step. For example, the first pulse can produce an electrical
ignition and an ionization of the electrical ignition coating 5,
and the following pulses can, in turn, generate an energy variance
in the formed plasma for controlling the combustion process of the
propellent charge 1 and the total pressure in the barrel during the
whole of the propulsion of the projectile part 17 through the
barrel.
[0071] Since the propellent charge 1 is burnt much more effectively
by the pulsed plasma, a pressure maximum will be obtained which is
higher for the same propellent charge 1 than in a comparable
conventional ignition, at the same time as one or more further
pressure increases can be obtained, which can be made to mutually
overlap such that the pressure troughs of the total pressure curve
are minimized, whereby the total pressure curve, throughout the
period for which the projectile is in the barrel, is kept as close
as possible to the maximum pressure permitted for the particular
barrel. Thus the optimal acceleration of the present projectile is
achieved for each particular barrel, and hence also the maximum
muzzle velocity and range for the particular weapon.
Alternative Embodiments
[0072] The invention is not limited to the shown embodiment, but
can be variously modified within the scope of the patent claims.
For example, an instantaneous flashover ignition and a controlled
progressive combustion of an explosive charge 1 can also be
applicable in other applications than in barrel weapons.
[0073] It will also be appreciated that, in addition to different
types of gunpowder, suitable alternative explosives may also be
considered. It will further be appreciated that said propellent
charge 1, which expediently has been shaped to fit inside and
against the inner side of the used type of ammunition case, can
obviously consist of just a singular propellent component 3, but
which propellent charge 1 normally comprises a plurality of smaller
propellant components 3 in the form of geometric units which are
arranged more or less closely together and/or are packed together
and which, depending on mutual placement in the composed propellent
charge configuration 1, are expediently given such outer surfaces
that each individual geometric unit precisely fits to the inner
side of the surrounding ammunition case 9, any projectile part 17
inserted in the propellent charge 1, and all other directly
adjoining other geometric units. It is also conceivable to compose
a propellent charge 1 from many different sorts of propellant
components 3, for example with respect to combustion speed,
combustion temperature, chemical composition, conductive ignition
coating or not, etc., which various propellant components 3 are
then arranged axially and radially in the propellent charge 1
according to their mutual characteristics.
[0074] The above-specified geometric units can have many different
lengths and volumes, such as grains, rods, blocks, disks, sheets,
tubes, bars, etc., and combinations thereof in different shapes and
cross sections, such as polygonal (triangular, rectangular, square,
etc.) and rounded (oval, crescent-shaped, cylindrical, etc.) or in
the shape of curved or rolled sheets. The geometric units are
normally also multiperforated with burning channels 2, i.e.
comprise a considerable number of perforations, cavities or holes,
etc. arranged at a predetermined distance apart, which, from the
outer side of the outer surface of the particular geometric unit,
can pass wholly or partially through in order, via the burning
channels 2, to increase the available free burning surface 4 of
said geometric unit.
[0075] The described perforations 2 constitute just a few
exemplifications among many. The perforation pattern can, of
course, be varied according to the burning lengths, the
progressivity and other characteristics which are desired for the
particular propellent charge 1.
[0076] The invention per se is not directly dependent on which
electrically conductive material(s) is/are incorporated in the
surface coating or the coating 5 or how the latter explicitly has
been realized, and, as can be seen from above, there are a number
of different electrically conductive metals, which have long been
known and can be applied with different known methods to, for
example, a gunpowder, in order to give this a suitable electrically
conductive surface coating 5. We can here add, however, that the
ignition coating 5, in addition to what has already been listed,
can also advantageously comprise titanium Ti, graphite C and other
semiconductors. Although a semiconductor, for example germanium Ge
or gallium arsenide GaAs, does not conduct electricity as well as a
conductor, nor does it exclude current conduction. An extra
advantage with the electrically conductive ignition coating 5
according to the invention is that this coating, as an extra bonus,
lends each propellant component 3 an effective moisture
protection.
[0077] As examples of some methods for providing the propellant in
question with a suitable conductive surface coating 5 can be cited
galvanization, plating, chemical steam deposition (vacuum
steaming), sputtering, dipping or painting with electrically
conductive paint. It is also proposed that a conductive coating of
electrically conductive material 5 is applied by means of glue, for
example an epoxy based conductive copper coating, which also lends
a certain flexibility.
[0078] The applied electrically conductive surface coating 5 should
be configured with respect to thickness and covering and should be
of such a composition that the surface coating 5 acquires an
electrical conductivity, suitable for the invention, over all
custom-made burning surfaces 4 and burning channels 2, at the same
time as a momentary vaporization and ionization of the surface
coating 5 is realized in the ignition of the propellent charge 1.
From this follows that the optimal surface coating 5 in the great
majority of cases will have a thickness of around one to a few
thousandths of a millimetre, and that the surface coating 5 is
disposed not only on the free outer surfaces 4 of each propellant
component 3, but also down into and on the inner burning surfaces 4
of all the burning channels 2.
[0079] According to a preferred embodiment of the invention
described in greater detail below, the propellant components 3
incorporated in the respective propellent charge 1 are comprised of
intrinsically specific products comprising multiperforated 2
propellant blocks, propellant sheets, propellant tubes, etc., which
already, individually, are prepared for electrical ignition and
progressive combustion, which propellant components 3 can thus be
combined into various types of propellent charges 1, whose
characteristics are determined according to ammunition and weapon
type, cartridge dimension, projectile type and desired effect for
the projectile type, and then specifically for such propellent
charges of which absolutely optimal characteristics, such as
maximum muzzle velocity and range in, in particular, combat vehicle
guns and extremely long-range artillery ordnance, are demanded.
[0080] Method for Electrical Flashover Ignition and Combustion of
Propellent Charge, as Well as Propellent Charge and Ammunition Shot
in Accordance Therewith [0081] 1. propellent charge/propellent
charge quantity [0082] 2. burning channels, multiperforated [0083]
3. propellant component, propellant block [0084] 4. burning
surfaces [0085] 5. electrically conductive surface coating/ignition
coating [0086] 6. high-voltage source [0087] 7. pulse unit [0088]
8. ammunition shot [0089] 9. cartridge case [0090] 10. electrical
insulation [0091] 11. smaller uninsulated region [0092] 12. neck
opening, cartridge case [0093] 13. input conductor [0094] 14.
output conductor [0095] 15. insulation sleeve [0096] 16. back piece
[0097] 17. projectile/projectile part [0098] 18. front end,
propellent charge
* * * * *